This invention relates generally to compaction of material under high pressure and temperature conditions produced within an explosive charge.
The positioning of carbonaceous material such as graphite within an explosive charge that is detonated to produce the high pressure and temperature conditions deemed necessary to compact the graphite into diamonds, is generally known in the art as disclosed for example in U.S. Pat. No. 3,238,019 to De Carli. Modification of the detonation phenomenon in explosive charges by formation of cavities therein through which detonation induced shock waves are propagated, is also well known in the art. Pulse pressure conditions associated with the detonation of explosive charges has been varied by such modification (referred to as a "channel effect"), primarily to increase the detonation velocity otherwise dependent only on the density and sensitivity of the explosive material. A "channel effect" modification of an explosive charge is disclosed for example in U.S. Pat. No. 4,402,270 to McCaffrey, wherein an otherwise continuous cavity channel is blocked at one or more locations therein to further increase the self-sustaining detonation velocity.
Other "channel effect" types of explosive charge modifications are now available. One of such other "channel effect" modifications includes a multiple cavity arrangement involving continuous channels in combination with blocked channels in a body of explosive material. Another modification involves plural continuous channels in radially spaced relation to a central continuous channel for compounding of the "channel effect" by interaction of shock waves in the respective channels. Still other "channel effect" modifications may be achieved by use of fibers as the explosive material, and by internally lining a continuous channel with a helically threaded formation to obtain periodic partial interruption of shock waves propagated through the channel, without pressure oscillations, in response to a detonation pulse.
It is an important object of the present invention to compact carbonaceous material by detonation of an explosive charge modified to improve the conditions under which compaction products, such as diamonds, are obtained.